反应详情

A mixture of 1-(3,4-dihydro-2H-chromen-6-yl)ethanone (3.80 g, 22.0 mmol) and sodium hypochlorite [150 mL of a 6.0% aqueous solution, (Clorox brand of bleach)] in a 55° C. oil bath is stirred for 2 h. The mixture (now homogeneous) is cooled to rt and solid sodium bisulfite is added until a clear color persisted. HCl (ca 15 mL of a 6.0 M aqueous solution) is added, followed by extraction with EtOAc. The organic layer is washed with brine, dried (MgSO4), filtered, and concentrated in vacuo to afford 3.10 g (82%) of chromane-6-carboxylic acid as a white solid. 1H NMR (400 MHz, DMSO-d6) δ 12.55, 7.67, 7.6, 6.79, 4.20, 2.77, 1.96-1.90.

1. extractionfollowed by extraction with EtOAc
2. washThe organic layer is washed with brine
3. dry with materialdried (MgSO4)
4. filtrationfiltered
5. concentrationconcentrated in vacuo